JP2000165820A - Image recording and reproducing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm a picture of a mobile object having already passed over without the need for photographing again on the occurrence of a defective picture. SOLUTION: A ring buffer 3 can write/read optionally endlessly an image signal obtained by continuously photographing a mobile object. A main memory 42 acts like an image storage section that reads and stores an image signal once written in the ring buffer. Furthermore, a timing/controller 22 controls the write/read of the ring buffer 3. Since an image of the mobile object having already passed over is stored in the ring buffer 3, the main memory 42 or an HDD 27, the image can be confirmed without the need for photographing the object again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording / reproducing method and apparatus for inspecting a running object such as a printed matter during printing and recording / reproducing a digital image of a defective image, and particularly when a defective image is generated. In addition, the present invention relates to an image recording / reproducing method and apparatus capable of confirming an image of a traveling object that has already gone too far without taking another image.

[0002]

2. Description of the Related Art In FIG. 1, reference numerals G1 to G4 denote, in this order, one-frame images obtained by imaging the appearance of a running object such as a printed matter being printed. That is, the currently obtained signal is assumed to be W4, and the image based on the signal W4 is assumed to be G4. Also, the obtained signals are W4, W3,
It is assumed that a new image becomes an old image in the order of W2 and W1.
G3, G2, and G1.

Conventionally, a signal of an image obtained at present can be stored, but an image before that is not stored.
For example, in FIG. 1, the current image G4 can be referred to, but the past images G3 to G1 cannot be referred to.

[0004] Therefore, for example, when inspecting a printed matter, if a printing defect is found in a currently obtained image, the defective image itself can be stored, but the previous image is not stored. For this reason, it is not possible to confirm whether the printing failure has occurred continuously from the past.

For example, in an image G4 of FIG.
It is assumed that stains on the printed matter are found. Even in this case, since the past images G3 to G1 cannot be confirmed conventionally, it was not possible to confirm that the stains of the codes A2 and A1 have already occurred in the images G3 and G2.

[0006]

For this reason, as shown in FIG. 2, it is conceivable that a camera C2 is installed at a distance L away from the camera C1 capturing the moving object 1. In this way, it is possible to obtain a past image by the time difference by using the time difference due to the travel of the distance L,
An image of the traveling object 1 that has already gone too far can be captured again. However, an extra facility called camera C2 is required. In addition, the distance L calculated based on the required time difference and based on the traveling speed of the traveling object 1 must be ensured, so that there is a problem that an installation space is required. If the required time difference is constant despite the change in the traveling speed, it is necessary to change the distance L in accordance with the change in the traveling speed. In this case, the installation position of the camera C2 must be moved. There is also a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. In the case where a defect image is generated, an image of a traveling object which has already gone too far can be confirmed without taking another image. An object of the present invention is to provide a recording and reproducing method and apparatus.

[0008]

First, an image recording / reproducing method according to a first invention of the present application is a method for recording / reproducing a defect image used in a visual inspection apparatus for a traveling object. The object has been achieved by writing an obtained image signal in a ring buffer for imaging and reading and writing endlessly and making it possible to refer to any past captured image written in the ring buffer.

Next, an image recording / reproducing apparatus according to a second aspect of the present invention is a defect image recording / reproducing apparatus used for a visual inspection apparatus for a traveling object, which is obtained by continuously imaging the traveling object while traveling. A ring buffer capable of writing and reading an image signal endlessly and arbitrarily; an image storage unit for reading and storing the image signal once written in the ring buffer; and controlling writing and reading of the ring buffer. With the provision of the timing controller, the above-mentioned problem is solved.

The image recording / reproducing apparatus according to the second aspect of the present invention includes one or more image input units, thereby providing one specific embodiment.

Further, the image recording / reproducing apparatus according to the second aspect of the present invention is provided with an image display section for displaying images stored in the image storage section, thereby improving the convenience of the apparatus. be able to.

Hereinafter, the operation of the present invention will be briefly described.

In the present invention, an image of a traveling object that has already gone too far is also stored in the ring buffer. Therefore, an image captured in the past can be obtained. If a plurality of past images are stored in the ring buffer, the past images can be easily obtained with various time differences. Therefore, even when the traveling speed of the traveling object changes, the past image can be obtained relatively easily by a necessary time difference without moving the installation position of the camera C2 as in the conventional example described above with reference to FIG. be able to.

As described above, according to the present invention, when a defect image is generated, an image of a traveling object that has already gone too far can be obtained.
It can be confirmed without taking another image.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 3 is a block diagram showing the configuration of the embodiment to which the present invention is applied.

In this embodiment, a CPU (centrifuge) connected to each other by a bus 5 including a data bus and an address bus.
ral processing unit) 40, main memory 42, HD
D (hard disk drive) controller 26 and HDD 2
7 and a display device 50, and the basic configuration is similar to a general-purpose computer device. The HDD 27 is connected to the HDD controller 26. The display device 50 includes a display controller 52.
And CRT (cathode lay tube) and LCD (liquidcrys
tal display) and a display memory 56.

In addition to such a configuration, the present embodiment has a camera 10 including an image pickup device 12 and an A / D converter 14. Further, the ring buffer 3 and the DM
An A (direct memory access) controller 24 and a timing controller 22 are provided. The DMA controller 24 transfers the image stored in the ring buffer 3 to the main memory 42 via the bus 5 or to the display memory 56 via the display controller 52 without requiring the processing of the CPU 40. I do. here,
The portion denoted by reference numeral 20 is a main portion to which the present invention is applied in the present embodiment.

FIG. 4 is an address map showing the configuration of the ring buffer 3 of the present embodiment.

In FIG. 1, writing and reading of image signals to and from the ring buffer 3 are performed in units of one frame. Each of the frame memories FM1 to FM16 is a 1 MB memory in the ring buffer 3,
You can write and save the image of the frame. The ring buffer 3 includes such frame memories FM1 to FM1.
There are 16 FM16s in total, and the storage capacity is 16 MB.

In this figure, reference numeral WP is a pointer indicating a position where the current image signal obtained from the camera 10 is to be written. The code RP is the frame memory FM
1 to 1 are pointers indicating the positions of image signals of one frame which are to be read arbitrarily in the FM 16.

In the present invention, writing to and reading from the ring buffer is not limited to one frame unit as described above. For example, in the case of a raster image image in which line images in a direction orthogonal to the traveling direction are sequentially obtained as the traveling object travels, the line images may be sequentially written to the ring buffer regardless of one frame. Even in such a case, by reading a line image of an arbitrary frame from the ring buffer, an arbitrary frame image in the ring buffer can be obtained.

In the present embodiment, the image storage for reading and storing the image signal once written in the ring buffer 3 as described above is a main memory 42 in the present embodiment.
It is. Further, since the image signal of the main memory 42 is written to the HDD 27 via the HDD controller 26, the HDD 27 can also be referred to as an image storage unit in the present invention.

Hereinafter, the operation of the present embodiment will be described.

Normally, an image is taken in synchronism with the running body, and the image is always written in the ring buffer 3. For example, as described above, for an image in which one frame is 1 MB,
If the ring buffer 3 is 16 MB, images of 16 frames can be stored continuously. When images more than the number of frames that can be written to the ring buffer 3 are written, old images are sequentially overwritten. For example, when 16 frames can be stored as described above, the 17th frame is overwritten, and the 17th frame is overwritten on the first frame.

The writing of an image in the ring buffer 3 is performed at the position indicated by the write pointer WP. Assuming that the number of frames that can be written to the ring buffer 3 is N, the write pointer WP takes a value from “0” to (N−1). Write pointer WP
Increases sequentially by “1” each time data is written to the ring buffer 3. When the value becomes equal to or larger than the number of frames that can be written in the ring buffer 3, the value of the write pointer WP becomes "0" again.

The reading of the image stored in the ring buffer 3 is performed only for an image that has already been written and has not been overwritten yet. Therefore, the image under such conditions is read using the read pointer RP indicating the read position of the ring buffer 3.

In the present embodiment, the image in the ring buffer 3 is transferred to the DMA controller 24,
Via a bus 5, a display controller 52, and a display memory 56, a display 54 such as a CRT as needed.
Can be displayed. Further, once a signal indicating the occurrence of a defect is transmitted from the outside to the timing controller 22, the DMA controller 24 transfers the image data of several frames before and after the image including the point of occurrence of the defect, stored in the ring buffer 3 to the main controller. It is temporarily saved in the memory 42. At this time, the auxiliary information such as the time, inspection state, and item information of each image is also saved in the main memory 42 at the same time. Then, C
The PU 40 stores these data in the main memory 42
The controller 26 is controlled to write data into the HDD 27.

When an instruction to reproduce a defective image is issued from the keyboards 44, the CPU 40 fetches a specified image from the HDD 27 and sends the specified image to the display controller 5.
2 is displayed on the display 54 by controlling.

FIG. 5 is a flowchart showing the processing of this embodiment.

The operation of this embodiment will be described below with reference to the flowchart.

In FIG. 5, first, at step 112,
Initialize the write pointer WP. In this embodiment,
Assuming that the number of frames that can be written to the ring buffer 3 is N, the write pointer WP changes from “0” to (N−1).
Take values up to. Therefore, in step 112, the value of the write pointer WP is set to “0”. That is, assuming that the value of the write pointer WP is i, an initial value is set as in the following equation. In the following description of the expression, ":
= ”Means that the value on the right side is assigned to the variable on the left side, that is, the value on the right side is stored in the memory (pointer) of the variable on the left side.
It means to write to.

I: = 0 (1)

In step 114, the image currently taken by the image pickup device 12 of the camera 10 is fetched via the A / D converter 14. In step 116, the image is written to the ring buffer 3. That is, the write pointer WP
Write to the position indicated by.

In step 120, an image inspection apparatus (appearance inspection apparatus) not shown in FIG. 3 determines whether or not the image has a defect. In the present embodiment, the target running object is a printed matter running on a printing press immediately after printing. Further, the image inspection apparatus inspects the printed matter for printing defects such as dirt. If it is determined in step 120 that there is a defect, the process proceeds to step 122. If not detected, step 132
Proceed to.

At step 122, the read pointer R
Initialize P. Assuming that the value of the read pointer RP is j, in the initialization, the value of the read pointer RP is set as in the following equation.

J: = i + 1 (2)

Subsequently, at step 124, the ring buffer 3 is read out by the processing of the DMA controller 24 and stored in the main memory 42. The image of the ring buffer 3 to be read is stored in the frame memory FM under the condition shown by the following equation.
1 to FM16. Here, in the following equation, “mod” means a remainder operation.

(J mod N) (3)

At step 128, the read pointer R
The value of P is increased by "1". That is, the value of the read pointer RP is set as shown by the following equation.

J: = j + 1 (4)

In step 130, the read pointer R
It is determined whether the value of P is appropriate. That is, it is determined whether the following equation is satisfied.

[0043]

(Equation 1)

At step 132, the write pointer W
The value of P is increased by "1". That is, the value of the write pointer WP is set as shown by the following equation.

I: = i + 1 (6)

In step 136, the write pointer W
It is determined whether the value of P is appropriate. That is, it is determined whether the following equation is satisfied.

I = N (7)

In step 138, the write pointer W
Initialize P. That is, an initial value is set as in the following equation.

I: = 0 (8)

As described above, in the present embodiment, the present invention can be effectively applied. Therefore, when a defect image occurs, an image of a traveling object that has already gone too far can be confirmed without taking another image.

For example, as in the prior art, the camera C1 shown in FIG.
The images before and after the defect detection can be stored without providing the camera C2 downstream of the camera. Therefore, there is no problem that an installation space for the camera C2 is required. Further, when the time difference to a required past image is constant despite the change in the traveling speed, the installation position of the camera C2 must be moved in order to change the distance L according to the change in the traveling speed. No problem.

In the present embodiment, even if the number of images that can be stored in the ring buffer 3 is limited, the images stored in the ring buffer 3 are stored in the main memory 42 before they are overwritten and disappear. By doing so, it is possible to record a real-time image for a long time. At present, the price of semiconductor memory is falling, and 1 GB (= 1024
It is not impossible to implement a memory of the order of MB), so that considerable images can be stored.

In addition, a conventional ITV (industrial televisio
In an image recording apparatus using n) or a VTR (video tape recorder), deterioration in image quality becomes a problem. However, in the present embodiment, since the digital image is stored as it is, there is no deterioration. For example, there is no deterioration compared to an analog image.
In some cases, it is also possible to increase the storage efficiency by applying a non-distorted or distorted image compression method.

[0054]

According to the present invention, when a defect image is generated, an image of a traveling object that has already gone too far can be confirmed without taking another image.

[Brief description of the drawings]

FIG. 1 is a diagram showing images obtained by sequentially capturing the appearance of a running object such as a printed matter being printed;

FIG. 2 is a side view of a case where a plurality of cameras are arranged to newly capture an image of a traveling object that has already gone too far.

FIG. 3 is a block diagram showing a configuration of an embodiment to which the present invention is applied;

FIG. 4 is an address map showing a configuration of a ring buffer of the embodiment.

FIG. 5 is a flowchart showing processing of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Running object 3 ... Ring buffer 5 ... Bus 10 ... Camera 12 ... Image pickup device 14 ... A / D converter 20 ... Main part of application of this invention 22 ... Timing controller 24 ... DMA controller 26 ... HDD controller 27 ... HDD 40 ... CPU 42 ... Main memory 44 ... Keyboards 50 ... Display device 52 ... Display controller 54 ... Display 56 ... Display memory

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideto Sakata 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. 5C022 AA01 AB68 AC42 AC69 5C053 FA23 FA27 GB40 JA16 KA04 LA01 LA06 LA11 5C054 AA01 AA05 CA04 CC03 CH01 EA07 EB05 HA03

Claims (4)

[Claims] An image recording and reproducing method for a defect image used in a visual inspection apparatus for a traveling object, comprising: continuously imaging the traveling object while traveling; writing an obtained image signal to a ring buffer for reading and writing endlessly; An image recording / reproducing method, wherein an arbitrary past captured image written in the ring buffer can be referred to. 2. An image recording / reproducing apparatus for a defect image used in a visual inspection apparatus for a traveling object, wherein an image signal obtained by continuously imaging the traveling object while traveling is endlessly written and arbitrarily read. And a timing controller for controlling writing and reading of the ring buffer, and an image storage unit for reading and storing the image signal once written in the ring buffer. Image recording and reproducing device. 3. An image recording / reproducing apparatus according to claim 2, further comprising one or more image input units. 4. The image recording / reproducing apparatus according to claim 2, further comprising an image display section for displaying an image stored in said image storage section. apparatus.